José Mourinho believes Wayne Rooney's desire to leave Manchester United is David Moyes's fault for suggesting the striker would be a second-choice player this season. Chelsea remain determined to sign Rooney despite having had two bids rejected and, with the sides set to meet at Old Trafford on Monday night, United are unlikely to appreciate the timing and nature of Mourinho's comments, which will be seen as an attempt to undermine Moyes.

Rooney fell out badly with Sir Alex Ferguson last season and his relationship with the club appeared beyond repair after he was said to have been left "angry and confused" by Moyes hinting last month that he might have to accept a squad role behind Robin van Persie. However, for all Rooney's unhappiness, he is yet to hand in a transfer request.

When it was put to Mourinho that he will be given a hot reception at Old Trafford on Monday , he reacted with bemusement. "They are against me?" Mourinho said. "But I didn't say [to Rooney] you will be a second-choice for me. And they are against me?

"We are trying to get a player that a manager told 'You will be a second option' for him. We are not going for Van Persie. They don't have to be against me. If I say Ramires is a second option for me and he plays when Lampard is tired or injured, if someone comes here to get Ramires, nobody is upset."

When Mourinho was asked if Moyes should shoulder the blame, his reply was unequivocal: "Of course." In that moment, questioning Moyes's managerial style, it felt as if battle lines had been drawn, though Mourinho then tried to distance himself from appearing too critical. "In every big team, I am not criticising, you have first options and second options, and those second options must be very good players," he said. "Of course big teams must have second choices. Big players too. The point is if the players are happy to accept that situation."

Chelsea will wait until after Monday night's match before making a third approach but they are mindful of United's reluctance to sell the England forward. The champions are adamant Rooney is going nowhere, especially not to a direct rival, and although Chelsea hope United's resolve will be tested by a higher offer, they are also making alternative arrangements.

They expect to complete the acrimonious £32m transfer of Willian from Anzhi Makhachkala this week, subject to a work permit hearing for the Brazilian on Wednesday, and are looking into the possibility of bringing his team-mate, Samuel Eto'o, to Stamford Bridge on a one-year deal as well. Mourinho worked with the striker for a season at Internazionale. However Eto'o's agent, who will be at Old Trafford on Monday night, was believed to be in Milan on Sunday, exploring the possibility of a better deal for the 32-year-old at Internazionale.

Rooney, who is 27, is Chelsea's primary target, the player Mourinho has identified to spearhead his attack. He has done little to hide his interest in signing Rooney, who is desperate to leave United, speaking frankly on several occasions about luring him to west London.

Rooney was on the bench when Mourinho's Real Madrid side visited United in the Champions League last season. However Mourinho certainly does not envisage him playing a bit-part role at Chelsea and is not bothered about the way he has fallen out of favour at United. "It means they have a fantastic squad," he said. "Fantastic. I was playing against them last year. He was on the bench and he [Ferguson] was playing Van Persie, [Danny] Welbeck, [Shinji] Kagawa. The squad is amazing. So it is natural that some players have to be second-choice."

Mourinho has said that he wants a 22-man squad and should Rooney or Eto'o sign before the transfer window shuts on 2 September, one of the trio of strikers who are currently at Chelsea's disposal may leave. Demba Ba is a likelier casualty than Romelu Lukaku or Fernando Torres. The arrival of Willian, an attacking midfielder who can play behind the striker on the left, will also increase competition for places in an area where Chelsea have an abundance of talent. However Mourinho continues to insist that Juan Mata, who has been linked with a move away, is part of his plans.

Willian had been expected to sign for Tottenham in a £30m deal from Anzhi after completing a medical with them on Thursday, only for Chelsea to enrage the north London club by stepping in with a higher offer. There was fury behind the scenes at Tottenham on Friday, as they claimed Chelsea's actions were part of a vendetta against them and designed to prevent André Villas-Boas from constructing a squad capable of challenging them in the Premier League this season. Chelsea strongly disputed that and said they have always had an interest in Willian.

Asked how long he has coveted him, Mourinho said: "Since I started watching him playing for Shakhtar Donetsk in the Champions League." He also denied that tempting the 25-year-old away from Tottenham was a way of getting one over Villas-Boas, who he worked with at Porto, Chelsea and Inter. "Purely business," Mourinho said.